The present invention relates to a valve assembly for a fluid control device. Particularly, the present invention relates to a concentric cartridge for the valve assembly for controlling fluid volume and fluid temperature.
Valve assemblies are used in a variety of plumbing fixtures for controlling the temperature and volume of water dispensed from the fixture. A valve assembly may receive hot water and cold water from separate supply lines and controllably mix the water to provide an output having an intermediate temperature.
Sequential valve assemblies use a single handle that, upon rotation, opens the valve and increases the volumetric flow rate to maximum flow of cold water. Continued rotation of the handle maintains the volumetric flow rate while increasing the temperature.
Other valve assemblies use two concentrically mounted handles or dials, one to control temperature and one to control volumetric flow rate. Such valve assemblies are typically referred to as “concentric” valves. Current concentric valves suffer from the disadvantage that the concentric controls are frequently interdependent. For example, turning the outer concentric volume control dial may cause the inner concentric temperature control dial to rotate. This results in the inability to set the desired temperature (e.g., by turning an inner concentric dial) until after the volumetric flow rate has been set (e.g., by turning the outer dial). Thus, a user may be required to set both temperature and flow rate sequentially each time the valve is operated.